Rheumatology (Oxford) 2018 May; 57(5):900-908Baricitinib (BARI) 2 or 4 mg had a beneficial treatment effect on patients with moderate to severe RA compared with placebo (PBO), irrespective of the number or nature of prior patient bDMARD use. The current therapeutic target for patients with established RA is low disease activity, but many patients fail to achieve this due to inadequate responses to DMARD therapies. With this patient population growing, therapies for these patients are considered one of the greatest unmet needs in RA. This subgroup analysis of RA-BEACON assessed the influence of patient demographics and clinical characteristics, and prior bDMARD use on response to BARI therapy. Efficacy was assessed using ACR20 response and low disease activity measured by CDAI≤10. Statistical analyses assessed significant quantitative or qualitative interactions across subgroups. With regard to baseline demographics and clinical characteristics, a significant quantitative interaction was observed in ACR20 response between BARI 4 mg compared with PBO by region. Additionally, a significant interaction was observed for CDAI≤10 for BARI 4 mg compared with PBO by disease duration.For the analysis by previous bDMARD experience, higher ACR20 response rates were noted for BARI 2 and 4 mg compared with PBO for patients stratified by last bDMARD prior to randomisation, regardless of which TNFi or non-TNFi inhibitor was used most recently before study enrolment. Other analyses showed no significant interactions across strata.The authors conclude that BARI dosed at 2 and 4 mg is a beneficial treatment for patients with moderate to severe RA, irrespective of previous bDMARD use. BARI had a consistent treatment effect across the strata, with no evidence of any qualitative interactions at Wks12 and 24. Because the number of patients with inadequate response to TNFis is increasing, this finding could be clinically relevant.